Facebook founder and CEO Mark Zuckerberg delivers the opening keynote address at the f8 Developer Conference April 21, 2010 in San Francisco, California. Zuckerberg kicked off the the one day conference for developers that features breakout sessions on the future of social technologies.

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The couple invited less than 100 friends and family members to their home over the weekend to celebrate Priscilla's graduation from med school, then they surprised their guests with a different sort of celebration—a wedding!

Mark and Priscilla—who have been together for nine years—exchanged vows in their backyard.